My web app running in EC2 is accessible to the world via AWS Public DNS. Is this good or bad?

I'm running a web app in EC2 and the it is accessible via mydomainname.com. however it's also accessible on AWS Public DNS which looks like ec2-xx-xxx-xxx-xx.compute-1.amazonaws.com. Im running nginx and I'm already redirecting my elastic IP to go to mydomainname.com. Can I redirect AWS Public DNS too the same way? Having the web app accessible via AWS Public DNS is good or bad?